FeignClient已经被定义的问题

一 具体报错信息如下

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-08-21 10:44:41.799 ERROR 59073 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

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APPLICATION FAILED TO START
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Description:

The bean 'xxxx-server.FeignClientSpecification' could not be registered. A bean with that name has already been defined and overriding is disabled.

Action:

Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true

Disconnected from the target VM, address: '127.0.0.1:63162', transport: 'socket'

Process finished with exit code 1

二 原因分析

定义的多个FeignClient接口的value都是xxxx-server，而Springboot2.2.x的bean名称是根据@FeignClient的value（即name）来命名的，导致bean已经被定义。

@FeignClient(value = "xxxx-server")
public interface Demo1Service {...}
  
@FeignClient(value = "xxxx-server")
public interface Demo2Service {...}

三 解决方案

方案一，按报错的提示，增加如下配置

spring.main.allow-bean-definition-overriding: true

方案二，在定义FeignClient的时候，同时定义一下contextId属性，会包含在beanName的规则里，就不会出现bean已经被定义的的异常了。

@FeignClient(value = "xxxx-server", contextId = "XXX1Service")

建议使用方案二，方案一可能存在一些未知的问题。